about_Types.ps1xml

TOPIC
about_Types.ps1xml
SHORT DESCRIPTION
Explains how to use Types.ps1xml files to extend the types of objects
that are used in Windows PowerShell.
LONG DESCRIPTION
Extended type data defines additional properties and methods ("members")
of object types in Windows PowerShell. There are two techniques for adding
extended type data to a Windows PowerShell session.
-- Types.ps1xml file: An XML file that defines extended type data.
-- Update-TypeData: A cmdlet that reloads Types.ps1xml files and defines
extended data for types in the current session.
This topic describes Types.ps1xml files. For more information about using the
Update-TypeData cmdlet to add dynamic extended type data to the current session
see Update-TypeData (http://go.microsoft.com/fwlink/?LinkID=113421).
About Extended Type Data
Extended type data defines additional properties and methods ("members")
of object types in Windows PowerShell. You can extend any type that is
supported by Windows PowerShell and use the added properties and methods
in the same way that you use the properties that are defined on the object
types.
For example, Windows PowerShell adds a DateTime property to all
System.DateTime objects, such as the ones that the Get-Date cmdlet
returns.
PS C:\> (Get-Date).DateTime
Sunday, January 29, 2012 9:43:57 AM
You won't find the DateTime property in the description of the System.DateTime
structure (http://msdn.microsoft.com/en-us/library/system.datetime.aspx),
because Windows PowerShell adds the property and it is visible only in
Windows PowerShell.
To add the DateTime property to all Windows PowerShell sessions, Windows PowerShell
defines the DateTime property in the Types.ps1xml file in the Windows PowerShell
installation directory ($pshome).
Adding Extended Type Data to Windows PowerShell.
There are three sources of extended type data in Windows PowerShell sessions.
-- The Types.ps1xml files in the Windows PowerShell installation directory
are loaded automatically into every Windows PowerShell session.
-- The Types.ps1xml files that modules export are loaded when the module
is imported into the current session.
-- Extended type data that is defined by using the Update-TypeData cmdlet
is added only to the current session. It is not saved in a file.
In the session, the extended type data from the three sources is applied
to objects in the same way and is available on all objects of the specified
types.
The TypeData Cmdlets
The following TypeData cmdlets are included in the Microsoft.PowerShell.Utility
module in Windows PowerShell 3.0 and later versions of Windows PowerShell.
Get-TypeData: Gets extended type data in the current session.
Update-TypeData: Reloads Types.ps1xml files. Adds extended type
data to the current session.
Remove-TypeData: Removes extended type data from the current
session.
For more information about these cmdlets, see the help topic for each
cmdlet.
Built-in Types.ps1xml Files
The Types.ps1xml files in the $pshome directory are added automatically to
every session.
The Types.ps1xml file in the Windows PowerShell installation directory
($pshome) is an XML-based text file that lets you add properties and
methods to the objects that are used in Windows PowerShell. Windows
PowerShell has built-in Types.ps1xml files that add several elements
to the .NET Framework types, but you can create additional Types.ps1xml
files to further extend the types.
For example, by default, array objects (System.Array) have a Length
property that lists the number of objects in the array. However, because
the name "length" does not clearly describe the property, Windows
PowerShell adds an alias property named "Count" that displays the same
value. The following XML adds the Count property to the System.Array type.
<Type>
<Name>System.Array</Name>
<Members>
<AliasProperty>
<Name>Count</Name>
<ReferencedMemberName>
Length
</ReferencedMemberName>
</AliasProperty>
</Members>
</Type>
To get the new AliasProperty, use a Get-Member command on any array, as shown
in the following example.
Get-Member -inputobject (1,2,3,4)
The command returns the following results.
Name MemberType Definition
---- ---------- ----------
Count AliasProperty Count = Length
Address Method System.Object& Address(Int32 )
Clone Method System.Object Clone()
CopyTo Method System.Void CopyTo(Array array, Int32 index):
Equals Method System.Boolean Equals(Object obj)
Get Method System.Object Get(Int32 )
...
As a result, you can use either the Count property or the Length property
of arrays in Windows PowerShell. For example:
C:\PS> (1, 2, 3, 4).count
4
C:\PS> (1, 2, 3, 4).length
4
Creating New Types.ps1xml Files
The .ps1xml files that are installed with Windows PowerShell are
digitally signed to prevent tampering because the formatting can include
script blocks. Therefore, to add a property or method to a .NET Framework
type, create your own Types.ps1xml files, and then add them to your
Windows PowerShell session.
To create a new file, start by copying an existing Types.ps1xml file. The
new file can have any name, but it must have a .ps1xml file name
extension. You can place the new file in any directory that is accessible
to Windows PowerShell, but it is useful to place the files in the Windows
PowerShell installation directory ($pshome) or in a subdirectory of the
installation directory.
When you have saved the new file, use the Update-TypeData cmdlet to add
the new file to your Windows PowerShell session. If you want your types
to take precedence over the types that are defined in the built-in file,
use the PrependData parameter of the Update-TypeData cmdlet.
Update-TypeData affects only the current session. To make the change to
all future sessions, export the console, or add the Update-TypeData
command to your Windows PowerShell profile.
Types.ps1xml and Add-Member
The Types.ps1xml files add properties and methods to all the instances
of the objects of the specified .NET Framework type in the affected
Windows PowerShell session. However, if you need to add properties or
methods only to one instance of an object, use the Add-Member cmdlet.
For more information,see Add-Member.
Example: Adding an Age Member to FileInfo Objects
This example shows how to add an Age property to file objects
(System.IO.FileInfo). The age of a file is the difference between
its creation time and the current time in days.
It is easiest to use the original Types.ps1xml file as a template
for the new file. The following command copies the original file to
a file called MyTypes.ps1xml in the $pshome directory.
copy-item Types.ps1xml MyTypes.ps1xml
Next, open the Types.ps1xml file in any XML or text editor, such
as Notepad. Because the Age property is calculated by using a script
block, find a <ScriptProperty> tag to use as a model for the new Age
property.
Copy the XML between the <Type> and </Type> tags of the code to create
the script property. Then, delete the remainder of the file, except for
the opening <?xml> and <Types> tags and the closing </Types> tag. You
must also delete the digital signature to prevent errors.
Begin with the model script property, such as the following script
property, which was copied from the original Types.ps1xml file.
<?xml version="1.0" encoding="utf-8" ?>
<Types>
<Type>
<Name>System.Guid</Name>
<Members>
<ScriptProperty>
<Name>Guid</Name>
<GetScriptBlock>$this.ToString()</GetScriptBlock>
</ScriptProperty>
</Members>
</Type>
</Types>
Then, change the name of the .NET Framework type, the name of the
property, and the value of the script block to create an Age property
for file objects.
<?xml version="1.0" encoding="utf-8" ?>
<Types>
<Type>
<Name>System.IO.FileInfo</Name>
<Members>
<ScriptProperty>
<Name>Age</Name>
<GetScriptBlock>
((get-date) - ($this.creationtime)).days
</GetScriptBlock>
</ScriptProperty>
</Members>
</Type>
</Types>
After you save the file and close it, run an Update-TypeData command,
such as the following command, to add the new Types.ps1xml file to the
current session. The command uses the PrependData parameter to place the
new file in a higher precedence order than the original file. (For more
information about Update-TypeData, see Update-TypeData.)
update-typedata -prependpath $pshome\MyTypes.ps1xml
To test the change, run a Get-ChildItem command to get the
PowerShell.exe file in the $pshome directory, and then pipe the file to
the Format-List cmdlet to list all of the properties of the file. As a
result of the change, the Age property appears in the list.
get-childitem $pshome\PowerShell.exe | format-list -property *
PSPath : Microsoft.PowerShell.Core\FileSystem::C:\WINDOWS...
PSParentPath : Microsoft.PowerShell.Core\FileSystem::C:\WINDOWS...
PSChildName : PowerShell.exe
PSDrive : C
PSProvider : Microsoft.PowerShell.Core\FileSystem
PSIsContainer : False
Age : 16
VersionInfo : File: C:\WINDOWS\system32\WindowsPow...
InternalName: POWERSHELL
OriginalFilename: PowerShell.EXE
...
You can also display the Age property of the file by using the following
command.
(get-childitem $pshome\PowerShell.exe).age
16
The XML in Types.ps1xml Files
The <Types> tag encloses all of the types that are defined in the file.
There should be only one pair of <Types> tags.
Each .NET Framework type mentioned in the file should be represented by
a pair of <Type> tags.
The type tags must contain the following tags:
<Name>: A pair of <Name> tags that enclose the name of the affected
.NET Framework type.
<Members>: A pair of <Members> tags that enclose the tags for the
new properties and methods that are defined for the
.NET Framework type.
Any of the following member tags can be inside the <Members> tags.
<AliasProperty>: Defines a new name for an existing property.
The <AliasProperty> tag must have a pair of <Name> tags that specify
the name of the new property and a pair of <ReferencedMemberName> tags
that specify the existing property.
For example, the Count alias property is an alias for the Length
property of array objects.
<Type>
<Name>System.Array</Name>
<Members>
<AliasProperty>
<Name>Count</Name>
<ReferencedMemberName>Length</ReferencedMemberName>
</AliasProperty>
</Members>
</Type>
<CodeMethod>: References a static method of a .NET Framework class.
The <CodeMethod> tag must have a pair of <Name> tags that specify
the name of the new method and a pair of <GetCodeReference> tags
that specify the code in which the method is defined.
For example, the Mode property of directories (System.IO.DirectoryInfo
objects) is a code property defined in the Windows PowerShell
FileSystem provider.
<Type>
<Name>System.IO.DirectoryInfo</Name>
<Members>
<CodeProperty>
<Name>Mode</Name>
<GetCodeReference>
<TypeName>Microsoft.PowerShell.Commands.FileSystemProvider</TypeName>
<MethodName>Mode</MethodName>
</GetCodeReference>
</CodeProperty>
</Members>
</Type>
<CodeProperty>: References a static method of a .NET Framework class.
The <CodeProperty> tag must have a pair of <Name> tags that specify
the name of the new property and a pair of <GetCodeReference> tags
that specify the code in which the property is defined.
For example, the Mode property of directories (System.IO.DirectoryInfo
objects) is a code property defined in the Windows PowerShell
FileSystem provider.
<Type>
<Name>System.IO.DirectoryInfo</Name>
<Members>
<CodeProperty>
<Name>Mode</Name>
<GetCodeReference>
<TypeName>Microsoft.PowerShell.Commands.FileSystemProvider</TypeName>
<MethodName>Mode</MethodName>
</GetCodeReference>
</CodeProperty>
</Members>
</Type>
<MemberSet>: Defines a collection of members (properties and methods).
The <MemberSet> tags appear within the primary <Members> tags. The
tags must enclose a pair of <Name> tags surrounding the name of the
member set and a pair of secondary <Members> tags that surround the
members (properties and methods) in the set. Any of the tags that
create a property (such as <NoteProperty> or <ScriptProperty>) or a
method (such as <Method> or <ScriptMethod>) can be members of the set.
In Types.ps1xml files, the <MemberSet> tag is used to define the
default views of the .NET Framework objects in Windows PowerShell. In
this case, the name of the member set (the value within the <Name>
tags) is always "PsStandardMembers", and the names of the properties
(the value of the <Name> tag) are one of the following:
- DefaultDisplayProperty: A single property of an object.
- DefaultDisplayPropertySet: One or more properties of an object.
- DefaultKeyPropertySet: One or more key properties of an object.
A key property identifies instances of property values, such as
the ID number of items in a session history.
For example, the following XML defines the default display of services
(System.ServiceProcess.ServiceController objects) that are returned by
the Get-Service cmdlet. It defines a member set named
"PsStandardMembers" that consists of a default property set with the
Status, Name, and DisplayName properties.
<Type>
<Name>System.ServiceProcess.ServiceController</Name>
<Members>
<MemberSet>
<Name>PSStandardMembers</Name>
<Members>
<PropertySet>
<Name>DefaultDisplayPropertySet</Name>
<ReferencedProperties>
<Name>Status</Name>
<Name>Name</Name>
<Name>DisplayName</Name>
</ReferencedProperties>
</PropertySet>
</Members>
</MemberSet>
</Members>
</Type>
<Method>: References a native method of the underlying object.
<Methods>: A collection of the methods of the object.
<NoteProperty>: Defines a property with a static value.
The <NoteProperty> tag must have a pair of <Name> tags that specify
the name of the new property and a pair of <Value> tags that specify
the value of the property.
For example, the following XML creates a Status property for
directories (System.IO.DirectoryInfo objects). The value of the
Status property is always "Success".
<Type>
<Name>System.IO.DirectoryInfo</Name>
<Members>
<NoteProperty>
<Name>Status</Name>
<Value>Success</Value>
</NoteProperty>
</Members>
</Type>
<ParameterizedProperty>: Properties that take arguments and return a
value.
<Properties>: A collection of the properties of the object.
<Property>: A property of the base object.
<PropertySet>: Defines a collection of properties of the object.
The <PropertySet> tag must have a pair of <Name> tags that specify
the name of the property set and a pair of <ReferencedProperty> tags
that specify the properties. The names of the properties are enclosed
in <Name> tag pairs.
In Types.ps1xml, <PropertySet> tags are used to define sets of
properties for the default display of an object. You can identify the
default displays by the value "PsStandardMembers" in the <Name> tag
of a <MemberSet> tag.
For example, the following XML creates a Status property for
directories (System.IO.DirectoryInfo objects). The value of the Status
property is always "Success".
<Type>
<Name>System.ServiceProcess.ServiceController</Name>
<Members>
<MemberSet>
<Name>PSStandardMembers</Name>
<Members>
<PropertySet>
<Name>DefaultDisplayPropertySet</Name>
<ReferencedProperties>
<Name>Status</Name
<Name>Name</Name>
<Name>DisplayName</Name>
</ReferencedProperties>
</PropertySet>
<Members>
<MemberSet>
<Members>
<Type>
<ScriptMethod>: Defines a method whose value is the output of a script.
The <ScriptMethod> tag must have a pair of <Name> tags that specify
the name of the new method and a pair of <Script> tags that enclose
the script block that returns the method result.
For example, the ConvertToDateTime and ConvertFromDateTime methods of
management objects (System.System.Management.ManagementObject) are
script methods that use the ToDateTime and ToDmtfDateTime static
methods of the System.Management.ManagementDateTimeConverter class.
<Type>
<Name>System.Management.ManagementObject</Name>
<Members>
<ScriptMethod>
<Name>ConvertToDateTime</Name>
<Script>
[System.Management.ManagementDateTimeConverter]::ToDateTime($args[0])
</Script>
</ScriptMethod>
<ScriptMethod>
<Name>ConvertFromDateTime</Name>
<Script>
[System.Management.ManagementDateTimeConverter]::ToDmtfDateTime($args[0])
</Script>
</ScriptMethod>
</Members>
</Type>
<ScriptProperty>: Defines a property whose value is the output of a
script.
The <ScriptProperty> tag must have a pair of <Name> tags that specify
the name of the new property and a pair of <GetScriptBlock> tags
that enclose the script block that returns the property value.
For example, the VersionInfo property of files (System.IO.FileInfo
objects) is a script property that results from using the FullName
property of the GetVersionInfo static method of
System.Diagnostics.FileVersionInfo objects.
<Type>
<Name>System.IO.FileInfo</Name>
<Members>
<ScriptProperty>
<Name>VersionInfo</Name>
<GetScriptBlock>
[System.Diagnostics.FileVersionInfo]::GetVersionInfo($this.FullName)
</GetScriptBlock>
</ScriptProperty>
</Members>
</Type>
For more information, see the Windows PowerShell Software Development
Kit (SDK) in the MSDN (Microsoft Developer Network )library
at http://go.microsoft.com/fwlink/?LinkId=144538.
Update-TypeData
To load your Types.ps1xml files into a Windows PowerShell session, run
the Update-TypeData cmdlet. If you want the types in your file to take
precedence over types in the built-in Types.ps1xml file, add the
PrependData parameter of Update-TypeData. Update-TypeData affects only
the current session. To make the change to all future sessions, export
the session, or add the Update-TypeData command to your Windows
PowerShell profile.
Exceptions that occur in properties, or from adding properties to an
Update-TypeData command, do not report errors to StdErr. This is to
suppress exceptions that would occur in many common types during formatting
and outputting. If you are getting .NET Framework properties, you can work
around the suppression of exceptions by using method syntax instead, as
shown in the following example:
"hello".get_Length()
Note that method syntax can only be used with .NET Framework properties.
Properties that are added by running the Update-TypeData cmdlet cannot
use method syntax.
Signing a Types.ps1xml File
To protect users of your Types.ps1xml file, you can sign the file using
a digital signature. For more information, see about_Signing.
SEE ALSO
about_Signing (http://go.microsoft.com/fwlink/?LinkID=113268)
Copy-Item (http://go.microsoft.com/fwlink/?LinkID=113292)
Copy-ItemProperty (http://go.microsoft.com/fwlink/?LinkID=113293)
Get-Member (http://go.microsoft.com/fwlink/?LinkID=113322)
Get-TypeData (http://go.microsoft.com/fwlink/?LinkID=217033)
Remove-TypeData (http://go.microsoft.com/fwlink/?LinkID=217038)
Update-TypeData (http://go.microsoft.com/fwlink/?LinkID=113421)